I have seen a lot of very different tutorials about how to remove blue lines from a scanned drawing. So I ask myself what is the best way in term of simplicity and quality to do this in Photoshop (CS3 and above).
And also, is the choice of the blue color really the best, or there are other better colors in order to obtain a clean final drawing with the sole black lines?
Image > Adjustments > Black & White.
Make colors blue and cyan as clear as you want until the blue lines disappear.
And thatÂ´s it.
(This solution works only on RGB mode.)